Loader assembly

ABSTRACT

An improved front end loader includes a pair of spaced-apart lift arms which are pivotally mounted on an articulated vehicle. Piston and cylinder assemblies pivot the lift arms to raise and lower a bucket. The bucket is pivoted between a plurality of operating positions upon actuation of a tilt linkage by a single piston and cylinder assembly. The tilt linkage and associated piston and cylinder assembly are located midway between the lift arms along a vertical plane extending through a longitudinal axis of the vehicle.

United States Patent 3,224,607 12/1965 Brown Paul H. Whitoomb Attica, N.Y.

June 19, 1969 Aug. 10, 1971 Eaton Yale & Towne Inc. Cleveland, Ohio lnventor Appl. No. Filed Patented Assignee LOADER ASSEMBLY 6 Claims, 6 Drawing Figs.

u.s.cu ht. C1. E02t3/74 Field of Search 214/776,

References Cited UNITED STATES PATENTS 3,447,708 6/1969 Steinkamp .1 214/775 FOREIGN PATENTS 753,008 7/1956 Great Britain 214/776 Primary Exam iner-Albert J. Maltay Attorney- Yount and Tarolli ABSTRACT: An improved front end loader includes a pair of spaced-apart lift arms which are pivotally mounted on an articulated vehicle. Piston and cylinder assemblies pivot the lift arms to raise and lower a bucket. The bucket is pivoted between a plurality of operating positions upon actuation of a tilt linkage by a single piston and cylinder assembly. The tilt linkage and associated piston and cylinder assembly are located midway between the lift arms along a vertical plane extending through a longitudinal axis of the vehicle.

PATENTEU we I 0 I87! SHEET 0F 3 FIG?) PATENTEI] ms I 0 IQYI SHEET 3 BF 3 LOADER ASSEMBLY The present invention relates generally to a new and improved load-handling apparatus and more particularly to a front end loader assembly.

An object of this invention is to provide a new and improved load-handling apparatus which is compact, reliable in operation, and adapted to be mounted on an articulated vehicle without interferring with relative movement between front and rear sections of the vehicle.

Another object of this invention is to provide a new and improved load-handling apparatus having a pair of lift arms for raising and lowering a bucket and a tilt linkage for quickly pivoting the bucket to facilitate loading and unloading the bucket.

Another object of this invention is to provide a new and improved load-handling apparatus including a pair of lift arms for raising a bucket and a tilt linkage for pivoting the bucket relative to the lift arms wherein the tilt linkage is operated by a single piston and cylinder assembly mounted midway between the lift arms.

Another object of this invention is to provide a new and improved load-handling apparatus including a pair of lift arms for raising and lowering a bucket and a tilt linkage for pivoting the bucket relative to the lift arms wherein the tilt linkage is mounted midway between the lift arms along a vertical plane extending through the central longitudinal axis of the vehicle.

Another object of this invention is to provide a new and improved load-handling apparatus including a pair of lift arms for raising and lowering a bucket and a tilt linkage for pivoting the bucket relative to the lift arms wherein raising and lowering of the lift arms results in a minimal movement of the bucket relative to the ground.

These and other features and objects of the invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of an articulated vehicle having a front end loader assembly constructed in accordance with the present invention;

FIG. 2 is a plan view, taken on a reduced scale generally along the line 2-2 of FIG. 1, illustrating the relationship of a pair of lift arms for raising and lowering a bucket relative to a tilt linkage and actuator cylinder for pivoting the bucket relative to the lift arms;

FIG. 3 is a schematic illustration of the front end loader with the bucket in a lowered position engaging a load;

FIG. 4 is a schematic illustration, generally similar to FIG. 3, illustrating the bucket in an upright position for raising or transporting a load;

FIG. 5 is a schematic illustration, generally similar to FIG. 4. illustrating the upright bucket in a raised position; and

FIG. 6 is a schematic illustration, generally similar to FIG. 5, illustrating the bucket in a dumping position.

The present invention provides a load-handling apparatus which includes a pair of spaced-apart lift arms which are pivotally connected to opposite sides ofa vehicle. A load-handling tool, a bucket in the illustrated embodiment of the invention, is pivotally mounted on the outer ends of the lift arms. The bucket is pivotal between a plurality of operating positions by operation of a single piston and cylinder assembly which is connected to the bucket by a tilt linkage. The single piston and cylinder assembly and tilt linkage are located midway between the lift arms along a longitudinal axis of the vehicle.

A front end loader 10 embodying the present invention is shown in FIG. I mounted on the front end section 12 of an articulated vehicle 14. The articulated vehicle 14 is of a known construction and includes relatively movable front and rear sections 12 and 16. The front end loader 10 includes a pair of lift arms and 22 which are pivotally connected at 24 and 26 with opposite sides of the vehicle 14. The lift arms 20 and 22 are located just inside the wheels 28 and 30 of the front section 12 and extend generally parallel to each other. The lift arms 20 and 22 terminate forwardly of the rear section 16 of the vehicle 14 so that theydo not interfere with pivotal movement of the front section 12 of the articulated vehicle relative to the rear section.

A load-engaging tool bucket 34 is pivotally connected at 36 and 38 (FIG. 2) to the forward or outer ends of the lift arms 20 and 22. A pair of hydraulic piston and cylinder assemblies 40 and 42 are pivotally connected at 44 and 46 to the front section 12 of the vehicle 14 and are pivotally connected at 48 and 50 to the lift arms 20 and 22. The piston cylinder assemblies 40 and 42 are operable between retracted and extended conditions to pivot the lift arms 20 and 22 relative to the vehicle 14 to thereby raise the bucket 34 from the lowered or load-en gaging position of FIGS. 1 and 3 to the raised or dumping position of FIG. 6.

The bucket 34 is pivoted relative to the lift arms 20 and 22 at the connections 36 and 38 by actuation of a tilt linkage 56. The tilt linkage 56 is located midway between the lift arms 20 and 22 along a vertical plane 58 extending through the longitudinal axis of the front section 12 (FIG. 2). The tilt linkage 56 is actuated by a single piston and cylinder assembly 60 (FIGS. 1 and 2) which is also located along the plane 58. When the bucket 34 is in the load-engaging position of FIG. 3, the bucket is held against pivoting movement about the connections 36 and 38 by the tilt linkage 56 and piston and cylinder assembly 60. After the bucket 34 has been moved into engagement with a pile of dirt or other material by forward movement of the vehicle 14, the bucket is broken away" or pivoted to an upright position (see FIG. 4) by operation of the tilt linkage 56 under the influence of piston and cylinder assembly 60.

Once the bucket has been pivoted to the upright position of FIG. 4, the piston and cylinder assemblies 40 and 42 are operated to pivot the lift arms 20 and 22 upwardly from the lowered position of FIG. 4 to the raised position of FIG. 5. During this upward movement of the lift arms, the bucket 34 is maintained in the upright position of FIG. 4 by the tilt linkage 56 and piston and cylinder assembly 60. Once the bucket 34 has been raised, the piston and cylinder assembly 60 is operated to actuate the tilt linkage 56 and pivot the bucket 34 to the dump position of FIG. 6 to thereby empty the-material out of the bucket.

The single piston and cylinder assembly 60 for actuating the tilt linkage 56 slopes upwardly and inwardly or rearwardly from a pivot connection 64 between the cylinder 66 and the forward end section 12 of the vehicle 14. The piston rod 68 of the assembly 60 is pivotally connected at 72 to an intermediate portion of a rear or inner tilt lever 76 of the tilt linkage 56. This orientation ofthe piston and cylinder assembly 60 results in the relatively large area of the head end of a piston associated with the piston rod 68 being exposed to fluid unde: pressure to actuate the tilt linkage 56 and pivot the bucket 34 during breakaway" or movement from the loading position of FIG. 3 to the upright position of FIG. 4. Therefore, the relatively large head end area of the piston is exposed to fluid pressure when the tilt linkage is subjected to relatively large breakaway" loads. When the bucket is pivoted from the upright position of FIG. 5 to the dump position of FIG. 6, the tilt linkage 56 is subjected to a relatively light load and the smaller rod end area of the piston is sufficient to actuate the tilt linkage.

In the specific preferred embodiment of the invention illustrated in the drawings, the pivot connection 64 for the cylinder 66 is immediately over the axis of rotation for the front wheels 28 and 30 of the vehicle 14. Since the piston and cylinder assembly 60 slopes upwardly and inwardly (FIG. 4), the line of action for the piston and cylinder assembly 60 intersects a horizontal plane through the axis of rotation for the wheels 28 and 30 at a point forwardly or outwardly of the axis. The piston and cylinder assemblies 40 and 42 for raising the lift arms 20 and 22 slope upwardly and forwardly or outwardly. Thus, the lines of action for the cylinders 40 and 42 intersect the horizontal plane through the axis or rotation of the front wheels 28 and 30 at a point inwardly or rearwardly of the axis.

The inner tilt lever 76 is pivotally connected at 80 with the forward section 12 of the vehicle 14 at a location outwardly of the lift arm pivot connections 24 and 26 and inwardly of the cylinder pivot connection 64. The connection 80 is, like the pivot connection 64 for the cylinder 66, located midway between the lift arms 20 and 22 along the vertical plane 58 extending through a longitudinal axis of the front section 12 of the vehicle The inner tilt lever 76 is connected with an outer tilt lever 84 by an inner tilt link 86 which includes a pair of parallel members pivotally connected at 88 to an intermediate portion of the outer tilt lever. The inner tilt link 86 is pivotally connected at 90 to an upper end of the inner tilt lever 76. The outer tilt lever 84 includes a pair of members pivotally connected at 96 to a cross section or piece 92 (FIG. 2) which extends between the lift arms 20 and 22. The pivot connection 96, like the pivot connections 64 and 80, is disposed midway between the lift arms 20 and 22 along the vertical plane 58 extending through the longitudinal axis of the front section 12 of the vehicle 14. The outer tilt lever 84 is in turn connected to the bucket 34 by an outer tilt link 100 which is pivotally connected at 102 to an upper end portion of the outer tilt lever 84 and to the bucket at pivot connection 104.

During operation of the front end loader 10, the bucket 34 is filled with dirt or other materials by driving the vehicle 14 forwardly toward a pile of dirt or other material with the bucket in the lowered, forwardly or outwardly facing position shown in FIG. 3. This forces the bucket 34 into the pile of dirt. The bucket is then broken away or pivoted to the upright position of FIG. 4. This accomplished by extending the piston and cylinder assembly 60 to pivot the inner tilt lever 76 rearwardly or inwardly about the connection 80 and thereby actuate the tilt linkage 56. Initiation of this inward pivoting movement of the tilt lever 76 is facilitated by a forward offsetting of the pivot connection 72 between the piston rod 68 and tilt lever relative to the pivot connection 80 at the bottom of the tilt lever 76 (see FIG. 3). This offsetting of the connection 72 relative to the connection 80 provides a lever arm to facilitate initial actuation of the tilt linkage 56 by the piston and cylinder assembly 60.

As the piston and cylinder assembly 60 of the illustrated embodimcnt of the invention is extended, the tilt lever 76 swings the pivot connection 90 about the pivot connection 80 from a position forwardly ofthe fixed pivot connections 24 and 26 for the lift arms 20 and 22 to a position rearwardly of the pivot connections 24 and 26 (see FIGS. 2, 3 and 4). In addition, the pivot connection 72 moves about the pivot connection 80 from a position forwardly of the pivot connections 48 and 50 to a position rearwardly of these connections. When the tilt lever 76 has been pivoted to its innermost position (FIG. 4), the inner tilt link 86 is intermediate the lift arms 20 and 22. This results in a relatively compact loader structure which can be moved relative to its surrounding environment with a minimum interference. In addition, when the bucket 34 is in the upright position of FIG. 4, the tilt linkage 56 is protected against damage by the sturdy lift arms and 22 and the wheels 28 and 30.

The bucket 34 is raised by extending the hydraulic piston and cylinder assemblies 40 and 42 (FIG. 5). During this up ward movement of the bucket 34, the inner tilt lever 76 is held against pivoting movement about the connection 80 by the piston and cylinder assembly 60. Since the outer tilt lever 84 is pivotally connected with the lift arms 20 and 22, upward movement of the lift arms results in the tilt linkage 56 being actuated to maintain the bucket in an upright position. It should be noted that the operation of the tilt linkage from the loading position of FIG. 3 to the upright position of FIG. 4 resulted in movement of the pivot connection 90. between the inner tilt lever 76 and tilt link 86. to a position closer to the pivot connections 24 and 26 for the lift arms 20 and 22. Pivot connection 90 in this position enables the tilt linkage 56 to tend to minimize changes in the angular orientation of the bucket 34 from the upright position of FIG. 4 as the bucket is raised.

To provide a relatively compact loader assembly 10 and to minimize the leverage of the bucket 34 relative to the piston and cylinder assemblies 40 and 42, the lift arms 20 and 22 project or extend for a relatively short distance forwardly or out wardly from the front section 12 of the vehicle 14. This relatively short forward extent of the lift arms 20 and 22, i.e. the horizontal distance between the pivot connections 24 and 26 to the vehicle 14 and the pivot connection 36 and 38 to the bucket 34 (FIG. 2), is due to the downwardly and outwardly sloping central portions of the lift arms 20 and 22 (FIG. 3). The downward slope of the lift arms 20 and 22 enables them to clear the mountings for the wheels 28 and 30 when the bucket 34 is in the lower position of FIGS. 1 and 2 without extending forwardly or outwardly for a relatively large distance. In the illustrated embodiment of the invention, the downward slope of the central or intermediate portion of the lift arms 20 and 22 is such that in the loading position of FIG. 3, the pivot connection I02 at the upper end of the tilt lever 84 is below the pivot connections 48 and 50 between the piston and cylinder assemblies 40 and 42 and the lift arms 20 and 22. In addition to minimizing the leverage which a load in the bucket 34 has against the piston and cylinder assemblies 40 and 42, the relatively short forward extent of the lift arms 20 and 22 enables the vehicle 14 to be readily maneuvered in relatively tight quarters.

Once the bucket 34 has been lifted to the raised position of FIG. 5, the bucket is dumped or empties by contracting the piston and cylinder assembly to actuate the tilt linkage 56. This contracting of the piston and cylinder assembly 60 pivots the inner tilt lever 76 outwardly from the position shown in FIG. 5 to the position shown in FIG. 6. Outward movement of the inner tilt lever 76 pivots the outer tilt lever 84 and bucket 34 forwardly relative to the lift arms 20 and 22 to enable the dirt or other material in the bucket to be dumped under the influence ofgravity.

After the bucket 34 has been emptied, the piston and cylinder assembly 60 is partially extended to pivot the bucket 34 back to the forwardly facing position of FIG. 3. Contemporaneously therewith, the lift arms 20 and 22 are pivoted downwardly to position the bucket for engagement with another load. It has been found that the tilt linkage 56 provides for a relatively quick pivoting movement of the bucket 34 between the various operating positions with a minimum of stress on the connections for the tilt linkage.

In view of the foregoing description, it can be seen that the tilt linkage 56 for the bucket 34 is disposed midway between the lift arms 20 and 22 along the plane 58 extending through the longitudinal axis of the front section 12 of the vehicle 14. In this location the tilt linkage 56 is protected by the lift arms 20 and 22 and can be actuated by a single piston and cylinder assembly 60. The piston and cylinder assembly 60 is also mounted with its longitudinal axis disposed in the vertical plane 58. By mounting the piston and cylinder assembly 60 with the relatively large head area of the piston associated exposed to high-pressure fluid during break away," that is the time when the greatest load is applied to the tilt linkage 56, the capabilities of the piston and cylinder assembly 60 are maximized. The relatively small rod end area of the piston is exposed to high-pressure fluid when a relatively light load is being applied to the tilt linkage 56.

Having described one embodiment of the invention, I claim:

I. Load-handling apparatus for moving a load relative to a vehicle, said load-handling apparatus comprising a pair of spaced-apart lift arms pivotally connected at their inner ends to opposite side portions of said vehicle, bucket means pivotally connected to outer ends of said lift arms for engaging a loud. said bucket mean having a first operating position in which it is adapted to engage a load and a second operating position in which is is adapted to transport a load, first piston and cylinder means for pivoting said lift arms relative to said vehicle to raise and lower said bucket means, tilt linkage means for pivoting said bucket means between said first and second operating positions, said tilt linkage means including an inner tilt lever pivotally connected at one end to said vehicle at a location outwardly of the pivotal connections between said lift arms and said vehicle, an outer tilt lever pivotally connected at one end with said lift arms at a location intermediate their inner and outer ends, an inner tilt link pivotally connected to the other end of said inner tilt lever and to an intermediate portion of said outer tilt lever, and an outer tilt link pivotally connected to an end of said outer tilt lever and to said bucket means, said lift arms extending outwardly and downwardly at such an angle that the interconnection between said outer tilt link and said outer tilt lever is below the interconnections between said first piston and cylinder assemblies and said lift arms when said bucket means is in a lowered position, and second piston and cylinder means pivotally connected at one end to said vehicle and sloping inwardly and upwardly to a pivotal connection to said inner tilt lever at a location intermediate the ends of said inner tilt lever, said second piston and cylinder means being operable to actuate said tilt linkage means to move said bucket means from said first operating position to said second operating position by pivoting said inner tilt lever relative to said vehicle in such a manner that the interconnection between said inner tilt lever and said inner tilt link moves toward the pivotal connections between said lift arms and said vehicle to thereby enable said tilt linkage means to tend to minimize movement of said bucket means from said second operating position upon raising and lowering ofsaid lift arms.

2. Load-handling apparatus as set forth in claim 1 wherein said second piston and cylinder means includes a single piston and cylinder assembly having a longitudinal axis located in a vertical plane extending through the longitudinal axis of said vehicle.

3. Load-handling apparatus as set forth in claim 2 wherein said inner tilt lever is connected to said vehicle and said outer tilt lever is pivotally connected with said lift arms at locations along the vertical plane extending through the longitudinal axis of said vehicle.

4. Load-handling apparatus as set forth in claim 1 wherein the longitudinal axes ofsaid first piston and cylinder means intersect a horizontal plane through the axis of rotation of the wheels of said vehicle on the inner side of the axis of rotation and the longitudinal axis of said second piston and cylinder means intersects the plane on the outer side of the axis of rotation of the vehicle wheels.

5. Load-handling apparatus as set forth in claim 1 wherein said second piston and cylinder means is pivotally connected to said vehicle at a location midway between said lift arms.

6. Load handling apparatus as set forth in claim I wherein said second piston and cylinder means includes a single hydraulic piston and cylinder assembly connected at the cylinder and thereof to said vehicle at a location outwardly of the connections between said lift arms and said vehicle and connected at the rod end thereof to said inner tilt lever at a location inwardly ofsaid cylinder and connection. 

1. Load-handling apparatus for moving a load relative to a vehicle, said load-handling apparatus comprising a pair of spaced-apart lift arms pivotally connected at their inner ends to opposite side portions of said vehicle, bucket means pivotally connected to outer ends of said lift arms for engaging a load, said bucket mean having a first operating position in which it is adapted to engage a load and a second operating position in which is is adapted to transport a load, first piston and cylinder means for pivoting said lift arms relative to said vehicle to raise and lower said bucket means, tilt linkage means for pivoting said bucket means between said first and second operating positions, said tilt linkage means including an inner tilt lever pivotally connected at one end to said vehicle at a location outwardly of the pivotal connections between said lift arms and said vehicle, an outer tilt lever pivotally connected at one end with said lift arms at a location intermediate their inner and outer ends, an inner tilt link pivotally connected to the other end of said inner tilt lever and to an intermediate portion of said outer tilt lever, and an outer tilt link pivotally connected to an end of said outer tilt lever and to said bucket means, said lift arms extending outwardly and downwardly at such an angle that the interconnection between said outer tilt link and said outer tilt lever is below the interconnections between said first piston and cylinder assemblies and said lift arms when said bucket means is in a lowered position, and second piston and cylinder means pivotally connected at one end to said vehicle and sloping inwardly and upwardly to a pivotal connection to said inner tilt lever at a location intermediate the ends of said inner tilt lever, said second piston and cylinder means being operable to actuate said tilt linkage means to move said bucket means from said first operating position to said second operating position by pivoting said inner tilt lever relative to said vehicle in such a manner that the interconnection between said inner tilt lever and said inner tilt link moves toward the pivotal connections between said lift arms and said vehicle to thereby enable said tilt linkage means to tend to minimize movement of said bucket means from said second operating position upon raising and lowering of said lift arms.
 2. Load-handling apparatus as set forth in claim 1 wherein said second piston and cylinder means includes a single piston and cylinder assembly having a longitudinal axis located in a vertical plane extending through the longitudinal axis of said vehicle.
 3. Load-handling apparatus as set forth in claim 2 wherein said inner tilt lever is connected to said vehicle and said outer tilt lever is pivotally connected with said lift arms at locations along the vertical plane extending through the longitudinal axis of said vehicle.
 4. Load-handling apparatus as set forth in claim 1 wherein the longitudinal axes of said first piston and cylinder means intersect a horizontal plane through the axis of rotation of the wheels of said vehicle on the inner side of the axis of rotation and the longitudinal axis of said second piston and cylinder means intersects the plane on the outer side of the axis of rotation of the vehicle wheels.
 5. Load-handling apparatus as set forth in claim 1 wherein said second piston and cylinder means is pivotally connected to said vehicle at a location midway between said lift arms.
 6. Load handling apparatus as set forth in claim 1 wherein said second piston and cylinder means includes a single hydraulic piston and cylinder assembly connected at the cylinder and thereof to said vehicle at a location outwardly of the connections between said lift arms and said vehicle and connected at the rod end thereof to said inner tilt lever at a location inwardly of said cylinder and connection. 